排序方式: 共有19条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
The effect of Gd content on microstructure and magnetic properties of sintered Nd33.03-xGdxFe65.65B1.32 (x=0-2) was studied in this paper to improve the thermal stability of NdFeB and to reduce the raw material cost. The results showed that better magnet performance could be obtained by adding Gd (0-1.5 wt.%) with partial substitution of Nd in Nd33.03-xGdxFe65.65B1.32. It was also found that the Nd33.03-xGdxFe65.65B1.32 magnets showed the best performance when Gd addition increased to 1.0 wt.%. The temperature coefficient Br (α) could be improved from -0.15%/oC to -0.063%/oC (maximum work temperature 120 oC) and the Curie temperature could be improved from 315 oC to 323 oC because the Gd2Fe14B had positive temperature coefficient Br (α) and higher Curie temperature than that of Nd2Fe14B. The coercivity could be improved from 10.2 to 11.48 kOe and the microstructure was close to ideal microstructure. The magnetic performance decreased sharply by adding Gd (above 2 wt.%) with partial substitution of Nd in Nd33.03-xGdxFe65.65B1.32 because the Gd element concen-trated in the grain boundaries. 相似文献
6.
7.
The thermo physical parameters of Tm vapor and the range of sublimation temperature were determined by vapor pressure of metal Tm, and a 2-D axis-symmetric heat transfer model was developed to investigate the temperature distribution in sublimation furnace. The simulation results showed that, due to the heat loss at crucible bottom, the temperature of crucible, solid metal and Tm vapor increased with crucible height increasing, reached the maximum value in the middle of crucible in height direction, and then decreased rapidly; at the outside surface of condenser, the temperature decreased sharply; with heating body temperature of 1000oC, the mean temperature at upper surface of solid Tm was 22oC higher than that on the lower surface, the mean temperature of upper surface of solid Tm was about 32oC lower than that of heating body, and the calculated sublimation velocity was 8.16g/cm2/h, which was only 54.4% of sublimation velocity calculation by heating body temperature. 相似文献
8.
9.
采用Si3N4结合SiC板作为3kA液态下阴极稀土金属电解槽的侧壁材料,进行了实际电解工艺试验,考察了Si3N4结合SiC材料在稀土熔盐电解槽上的使用效果,研究表明,Si3N4结合SiC材料在稀土熔盐中腐蚀较严重,尤其是靠近电解槽阴极位置,由于弥散在电解质中的金属雾和阳极产生的气体加剧了Si3N4结合SiC材料受腐蚀破坏;板材由于受热不均产生了开裂现象,且开裂位置会加剧材料的腐蚀破坏,进一步的分析表明,Si3N4结合SiC材料在稀土熔盐中主要受腐蚀的是含Si3N4的结合相。 相似文献
10.
稀土元素Sm对Mg-Zn-Y合金组织结构和力学性能的影响 总被引:1,自引:0,他引:1
制备了Mg-6Zn-1.5Y-0.8Zr-xSm(x=0,1,2,3)系列合金,研究了稀土元素Sm对Mg-6Zn-1.5Y-0.8Zr合金组织结构和力学性能的影响.通过金相显微镜、扫描电镜、EDS、XRD等观察和分析了合金的微观形貌和组织结构,测量了合金抗拉强度、屈服强度和伸长率等力学性能.结果表明:合金中添加稀土元素Sm后晶粒有了明显的细化,随着Sm元素含量的增加,晶粒细化效果更为明显;通过XRD分析,添加Sm元素后,合金中并没有出现新的含Sm的物相,通过扫描电镜和EDS分析表明,合金中加入的Sm置换了部分Y,形成了Mg3( SmY)2 Zn3,Mg3( SmY) Zn6的相结构,Sm元素对Y的置换主要出现在Mg3( SmY) Zn6结构当中,在Mg3 (SmY) Zn6相结构出现较少;力学性能测试结果表明,随着Sm含量增多,合金晶粒细化,细晶强化作用明显,合金屈服强度逐渐增大,而抗拉强度和伸长率在Sm含量为2%时达到最大,比未添加Sm元素时提高约15%以上. 相似文献